intel-pt-decoder.c 66.2 KB
Newer Older
A
Adrian Hunter 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/*
 * intel_pt_decoder.c: Intel Processor Trace support
 * Copyright (c) 2013-2014, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <inttypes.h>
25
#include <linux/compiler.h>
A
Adrian Hunter 已提交
26 27 28

#include "../cache.h"
#include "../util.h"
29
#include "../auxtrace.h"
A
Adrian Hunter 已提交
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67

#include "intel-pt-insn-decoder.h"
#include "intel-pt-pkt-decoder.h"
#include "intel-pt-decoder.h"
#include "intel-pt-log.h"

#define INTEL_PT_BLK_SIZE 1024

#define BIT63 (((uint64_t)1 << 63))

#define INTEL_PT_RETURN 1

/* Maximum number of loops with no packets consumed i.e. stuck in a loop */
#define INTEL_PT_MAX_LOOPS 10000

struct intel_pt_blk {
	struct intel_pt_blk *prev;
	uint64_t ip[INTEL_PT_BLK_SIZE];
};

struct intel_pt_stack {
	struct intel_pt_blk *blk;
	struct intel_pt_blk *spare;
	int pos;
};

enum intel_pt_pkt_state {
	INTEL_PT_STATE_NO_PSB,
	INTEL_PT_STATE_NO_IP,
	INTEL_PT_STATE_ERR_RESYNC,
	INTEL_PT_STATE_IN_SYNC,
	INTEL_PT_STATE_TNT,
	INTEL_PT_STATE_TIP,
	INTEL_PT_STATE_TIP_PGD,
	INTEL_PT_STATE_FUP,
	INTEL_PT_STATE_FUP_NO_TIP,
};

68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
{
	switch (pkt_state) {
	case INTEL_PT_STATE_NO_PSB:
	case INTEL_PT_STATE_NO_IP:
	case INTEL_PT_STATE_ERR_RESYNC:
	case INTEL_PT_STATE_IN_SYNC:
	case INTEL_PT_STATE_TNT:
		return true;
	case INTEL_PT_STATE_TIP:
	case INTEL_PT_STATE_TIP_PGD:
	case INTEL_PT_STATE_FUP:
	case INTEL_PT_STATE_FUP_NO_TIP:
		return false;
	default:
		return true;
	};
}

A
Adrian Hunter 已提交
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
#ifdef INTEL_PT_STRICT
#define INTEL_PT_STATE_ERR1	INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_NO_PSB
#else
#define INTEL_PT_STATE_ERR1	(decoder->pkt_state)
#define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_IP
#define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_ERR_RESYNC
#define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_IN_SYNC
#endif

struct intel_pt_decoder {
	int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
	int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
			 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
			 uint64_t max_insn_cnt, void *data);
104
	bool (*pgd_ip)(uint64_t ip, void *data);
A
Adrian Hunter 已提交
105 106 107 108 109
	void *data;
	struct intel_pt_state state;
	const unsigned char *buf;
	size_t len;
	bool return_compression;
110
	bool branch_enable;
111
	bool mtc_insn;
A
Adrian Hunter 已提交
112
	bool pge;
113
	bool have_tma;
114
	bool have_cyc;
115
	bool fixup_last_mtc;
A
Adrian Hunter 已提交
116
	bool have_last_ip;
117
	enum intel_pt_param_flags flags;
A
Adrian Hunter 已提交
118 119 120 121 122 123 124
	uint64_t pos;
	uint64_t last_ip;
	uint64_t ip;
	uint64_t cr3;
	uint64_t timestamp;
	uint64_t tsc_timestamp;
	uint64_t ref_timestamp;
125
	uint64_t sample_timestamp;
A
Adrian Hunter 已提交
126
	uint64_t ret_addr;
127 128
	uint64_t ctc_timestamp;
	uint64_t ctc_delta;
129 130
	uint64_t cycle_cnt;
	uint64_t cyc_ref_timestamp;
131 132 133 134 135 136 137
	uint32_t last_mtc;
	uint32_t tsc_ctc_ratio_n;
	uint32_t tsc_ctc_ratio_d;
	uint32_t tsc_ctc_mult;
	uint32_t tsc_slip;
	uint32_t ctc_rem_mask;
	int mtc_shift;
A
Adrian Hunter 已提交
138 139 140 141 142 143
	struct intel_pt_stack stack;
	enum intel_pt_pkt_state pkt_state;
	struct intel_pt_pkt packet;
	struct intel_pt_pkt tnt;
	int pkt_step;
	int pkt_len;
144
	int last_packet_type;
A
Adrian Hunter 已提交
145
	unsigned int cbr;
146
	unsigned int cbr_seen;
A
Adrian Hunter 已提交
147
	unsigned int max_non_turbo_ratio;
148 149 150 151
	double max_non_turbo_ratio_fp;
	double cbr_cyc_to_tsc;
	double calc_cyc_to_tsc;
	bool have_calc_cyc_to_tsc;
A
Adrian Hunter 已提交
152 153 154 155
	int exec_mode;
	unsigned int insn_bytes;
	uint64_t period;
	enum intel_pt_period_type period_type;
156
	uint64_t tot_insn_cnt;
A
Adrian Hunter 已提交
157 158 159 160 161 162 163
	uint64_t period_insn_cnt;
	uint64_t period_mask;
	uint64_t period_ticks;
	uint64_t last_masked_timestamp;
	bool continuous_period;
	bool overflow;
	bool set_fup_tx_flags;
164 165 166 167
	bool set_fup_ptw;
	bool set_fup_mwait;
	bool set_fup_pwre;
	bool set_fup_exstop;
A
Adrian Hunter 已提交
168 169
	unsigned int fup_tx_flags;
	unsigned int tx_flags;
170 171 172
	uint64_t fup_ptw_payload;
	uint64_t fup_mwait_payload;
	uint64_t fup_pwre_payload;
173
	uint64_t cbr_payload;
A
Adrian Hunter 已提交
174
	uint64_t timestamp_insn_cnt;
175
	uint64_t sample_insn_cnt;
A
Adrian Hunter 已提交
176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205
	uint64_t stuck_ip;
	int no_progress;
	int stuck_ip_prd;
	int stuck_ip_cnt;
	const unsigned char *next_buf;
	size_t next_len;
	unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
};

static uint64_t intel_pt_lower_power_of_2(uint64_t x)
{
	int i;

	for (i = 0; x != 1; i++)
		x >>= 1;

	return x << i;
}

static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
{
	if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
		uint64_t period;

		period = intel_pt_lower_power_of_2(decoder->period);
		decoder->period_mask  = ~(period - 1);
		decoder->period_ticks = period;
	}
}

206 207 208 209 210 211 212
static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
{
	if (!d)
		return 0;
	return (t / d) * n + ((t % d) * n) / d;
}

A
Adrian Hunter 已提交
213 214 215 216 217 218 219 220 221 222 223 224 225
struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
{
	struct intel_pt_decoder *decoder;

	if (!params->get_trace || !params->walk_insn)
		return NULL;

	decoder = zalloc(sizeof(struct intel_pt_decoder));
	if (!decoder)
		return NULL;

	decoder->get_trace          = params->get_trace;
	decoder->walk_insn          = params->walk_insn;
226
	decoder->pgd_ip             = params->pgd_ip;
A
Adrian Hunter 已提交
227 228
	decoder->data               = params->data;
	decoder->return_compression = params->return_compression;
229
	decoder->branch_enable      = params->branch_enable;
A
Adrian Hunter 已提交
230

231 232
	decoder->flags              = params->flags;

A
Adrian Hunter 已提交
233 234 235
	decoder->period             = params->period;
	decoder->period_type        = params->period_type;

236 237
	decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
	decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
A
Adrian Hunter 已提交
238 239 240

	intel_pt_setup_period(decoder);

241 242 243 244 245 246 247 248 249 250 251 252 253 254
	decoder->mtc_shift = params->mtc_period;
	decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;

	decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
	decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;

	if (!decoder->tsc_ctc_ratio_n)
		decoder->tsc_ctc_ratio_d = 0;

	if (decoder->tsc_ctc_ratio_d) {
		if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
			decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
						decoder->tsc_ctc_ratio_d;
	}
A
Adrian Hunter 已提交
255 256 257 258 259 260 261 262

	/*
	 * A TSC packet can slip past MTC packets so that the timestamp appears
	 * to go backwards. One estimate is that can be up to about 40 CPU
	 * cycles, which is certainly less than 0x1000 TSC ticks, but accept
	 * slippage an order of magnitude more to be on the safe side.
	 */
	decoder->tsc_slip = 0x10000;
263 264 265 266 267 268 269

	intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
	intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
	intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
	intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
	intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);

A
Adrian Hunter 已提交
270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390
	return decoder;
}

static void intel_pt_pop_blk(struct intel_pt_stack *stack)
{
	struct intel_pt_blk *blk = stack->blk;

	stack->blk = blk->prev;
	if (!stack->spare)
		stack->spare = blk;
	else
		free(blk);
}

static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
{
	if (!stack->pos) {
		if (!stack->blk)
			return 0;
		intel_pt_pop_blk(stack);
		if (!stack->blk)
			return 0;
		stack->pos = INTEL_PT_BLK_SIZE;
	}
	return stack->blk->ip[--stack->pos];
}

static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
{
	struct intel_pt_blk *blk;

	if (stack->spare) {
		blk = stack->spare;
		stack->spare = NULL;
	} else {
		blk = malloc(sizeof(struct intel_pt_blk));
		if (!blk)
			return -ENOMEM;
	}

	blk->prev = stack->blk;
	stack->blk = blk;
	stack->pos = 0;
	return 0;
}

static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
{
	int err;

	if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
		err = intel_pt_alloc_blk(stack);
		if (err)
			return err;
	}

	stack->blk->ip[stack->pos++] = ip;
	return 0;
}

static void intel_pt_clear_stack(struct intel_pt_stack *stack)
{
	while (stack->blk)
		intel_pt_pop_blk(stack);
	stack->pos = 0;
}

static void intel_pt_free_stack(struct intel_pt_stack *stack)
{
	intel_pt_clear_stack(stack);
	zfree(&stack->blk);
	zfree(&stack->spare);
}

void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
{
	intel_pt_free_stack(&decoder->stack);
	free(decoder);
}

static int intel_pt_ext_err(int code)
{
	switch (code) {
	case -ENOMEM:
		return INTEL_PT_ERR_NOMEM;
	case -ENOSYS:
		return INTEL_PT_ERR_INTERN;
	case -EBADMSG:
		return INTEL_PT_ERR_BADPKT;
	case -ENODATA:
		return INTEL_PT_ERR_NODATA;
	case -EILSEQ:
		return INTEL_PT_ERR_NOINSN;
	case -ENOENT:
		return INTEL_PT_ERR_MISMAT;
	case -EOVERFLOW:
		return INTEL_PT_ERR_OVR;
	case -ENOSPC:
		return INTEL_PT_ERR_LOST;
	case -ELOOP:
		return INTEL_PT_ERR_NELOOP;
	default:
		return INTEL_PT_ERR_UNK;
	}
}

static const char *intel_pt_err_msgs[] = {
	[INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
	[INTEL_PT_ERR_INTERN] = "Internal error",
	[INTEL_PT_ERR_BADPKT] = "Bad packet",
	[INTEL_PT_ERR_NODATA] = "No more data",
	[INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
	[INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
	[INTEL_PT_ERR_OVR]    = "Overflow packet",
	[INTEL_PT_ERR_LOST]   = "Lost trace data",
	[INTEL_PT_ERR_UNK]    = "Unknown error!",
	[INTEL_PT_ERR_NELOOP] = "Never-ending loop",
};

int intel_pt__strerror(int code, char *buf, size_t buflen)
{
391
	if (code < 1 || code >= INTEL_PT_ERR_MAX)
A
Adrian Hunter 已提交
392 393 394 395 396
		code = INTEL_PT_ERR_UNK;
	strlcpy(buf, intel_pt_err_msgs[code], buflen);
	return 0;
}

397
static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
A
Adrian Hunter 已提交
398 399 400 401 402
				 uint64_t last_ip)
{
	uint64_t ip;

	switch (packet->count) {
403
	case 1:
A
Adrian Hunter 已提交
404 405 406
		ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
		     packet->payload;
		break;
407
	case 2:
A
Adrian Hunter 已提交
408 409 410
		ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
		     packet->payload;
		break;
411 412 413 414 415 416 417 418 419 420
	case 3:
		ip = packet->payload;
		/* Sign-extend 6-byte ip */
		if (ip & (uint64_t)0x800000000000ULL)
			ip |= (uint64_t)0xffff000000000000ULL;
		break;
	case 4:
		ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
		     packet->payload;
		break;
A
Adrian Hunter 已提交
421 422 423 424 425 426 427 428 429 430 431 432
	case 6:
		ip = packet->payload;
		break;
	default:
		return 0;
	}

	return ip;
}

static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
{
433
	decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
A
Adrian Hunter 已提交
434
	decoder->have_last_ip = true;
A
Adrian Hunter 已提交
435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
}

static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
{
	intel_pt_set_last_ip(decoder);
	decoder->ip = decoder->last_ip;
}

static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
{
	intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
			    decoder->buf);
}

static int intel_pt_bug(struct intel_pt_decoder *decoder)
{
	intel_pt_log("ERROR: Internal error\n");
	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
	return -ENOSYS;
}

static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
{
	decoder->tx_flags = 0;
}

static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
{
	decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
}

static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
{
	intel_pt_clear_tx_flags(decoder);
469
	decoder->have_tma = false;
A
Adrian Hunter 已提交
470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501
	decoder->pkt_len = 1;
	decoder->pkt_step = 1;
	intel_pt_decoder_log_packet(decoder);
	if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
		intel_pt_log("ERROR: Bad packet\n");
		decoder->pkt_state = INTEL_PT_STATE_ERR1;
	}
	return -EBADMSG;
}

static int intel_pt_get_data(struct intel_pt_decoder *decoder)
{
	struct intel_pt_buffer buffer = { .buf = 0, };
	int ret;

	decoder->pkt_step = 0;

	intel_pt_log("Getting more data\n");
	ret = decoder->get_trace(&buffer, decoder->data);
	if (ret)
		return ret;
	decoder->buf = buffer.buf;
	decoder->len = buffer.len;
	if (!decoder->len) {
		intel_pt_log("No more data\n");
		return -ENODATA;
	}
	if (!buffer.consecutive) {
		decoder->ip = 0;
		decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
		decoder->ref_timestamp = buffer.ref_timestamp;
		decoder->timestamp = 0;
502
		decoder->have_tma = false;
A
Adrian Hunter 已提交
503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563
		decoder->state.trace_nr = buffer.trace_nr;
		intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
			     decoder->ref_timestamp);
		return -ENOLINK;
	}

	return 0;
}

static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
{
	if (!decoder->next_buf)
		return intel_pt_get_data(decoder);

	decoder->buf = decoder->next_buf;
	decoder->len = decoder->next_len;
	decoder->next_buf = 0;
	decoder->next_len = 0;
	return 0;
}

static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
{
	unsigned char *buf = decoder->temp_buf;
	size_t old_len, len, n;
	int ret;

	old_len = decoder->len;
	len = decoder->len;
	memcpy(buf, decoder->buf, len);

	ret = intel_pt_get_data(decoder);
	if (ret) {
		decoder->pos += old_len;
		return ret < 0 ? ret : -EINVAL;
	}

	n = INTEL_PT_PKT_MAX_SZ - len;
	if (n > decoder->len)
		n = decoder->len;
	memcpy(buf + len, decoder->buf, n);
	len += n;

	ret = intel_pt_get_packet(buf, len, &decoder->packet);
	if (ret < (int)old_len) {
		decoder->next_buf = decoder->buf;
		decoder->next_len = decoder->len;
		decoder->buf = buf;
		decoder->len = old_len;
		return intel_pt_bad_packet(decoder);
	}

	decoder->next_buf = decoder->buf + (ret - old_len);
	decoder->next_len = decoder->len - (ret - old_len);

	decoder->buf = buf;
	decoder->len = ret;

	return ret;
}

564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624
struct intel_pt_pkt_info {
	struct intel_pt_decoder	  *decoder;
	struct intel_pt_pkt       packet;
	uint64_t                  pos;
	int                       pkt_len;
	int                       last_packet_type;
	void                      *data;
};

typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);

/* Lookahead packets in current buffer */
static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
				  intel_pt_pkt_cb_t cb, void *data)
{
	struct intel_pt_pkt_info pkt_info;
	const unsigned char *buf = decoder->buf;
	size_t len = decoder->len;
	int ret;

	pkt_info.decoder          = decoder;
	pkt_info.pos              = decoder->pos;
	pkt_info.pkt_len          = decoder->pkt_step;
	pkt_info.last_packet_type = decoder->last_packet_type;
	pkt_info.data             = data;

	while (1) {
		do {
			pkt_info.pos += pkt_info.pkt_len;
			buf          += pkt_info.pkt_len;
			len          -= pkt_info.pkt_len;

			if (!len)
				return INTEL_PT_NEED_MORE_BYTES;

			ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
			if (!ret)
				return INTEL_PT_NEED_MORE_BYTES;
			if (ret < 0)
				return ret;

			pkt_info.pkt_len = ret;
		} while (pkt_info.packet.type == INTEL_PT_PAD);

		ret = cb(&pkt_info);
		if (ret)
			return 0;

		pkt_info.last_packet_type = pkt_info.packet.type;
	}
}

struct intel_pt_calc_cyc_to_tsc_info {
	uint64_t        cycle_cnt;
	unsigned int    cbr;
	uint32_t        last_mtc;
	uint64_t        ctc_timestamp;
	uint64_t        ctc_delta;
	uint64_t        tsc_timestamp;
	uint64_t        timestamp;
	bool            have_tma;
625
	bool            fixup_last_mtc;
626 627 628 629
	bool            from_mtc;
	double          cbr_cyc_to_tsc;
};

630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649
/*
 * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
 * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
 * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
 * packet by copying the missing bits from the current MTC assuming the least
 * difference between the two, and that the current MTC comes after last_mtc.
 */
static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
				    uint32_t *last_mtc)
{
	uint32_t first_missing_bit = 1U << (16 - mtc_shift);
	uint32_t mask = ~(first_missing_bit - 1);

	*last_mtc |= mtc & mask;
	if (*last_mtc >= mtc) {
		*last_mtc -= first_missing_bit;
		*last_mtc &= 0xff;
	}
}

650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671
static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct intel_pt_decoder *decoder = pkt_info->decoder;
	struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
	uint64_t timestamp;
	double cyc_to_tsc;
	unsigned int cbr;
	uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;

	switch (pkt_info->packet.type) {
	case INTEL_PT_TNT:
	case INTEL_PT_TIP_PGE:
	case INTEL_PT_TIP:
	case INTEL_PT_FUP:
	case INTEL_PT_PSB:
	case INTEL_PT_PIP:
	case INTEL_PT_MODE_EXEC:
	case INTEL_PT_MODE_TSX:
	case INTEL_PT_PSBEND:
	case INTEL_PT_PAD:
	case INTEL_PT_VMCS:
	case INTEL_PT_MNT:
672 673
	case INTEL_PT_PTWRITE:
	case INTEL_PT_PTWRITE_IP:
674 675 676 677 678 679 680
		return 0;

	case INTEL_PT_MTC:
		if (!data->have_tma)
			return 0;

		mtc = pkt_info->packet.payload;
681 682 683 684 685
		if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
			data->fixup_last_mtc = false;
			intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
						&data->last_mtc);
		}
686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
		if (mtc > data->last_mtc)
			mtc_delta = mtc - data->last_mtc;
		else
			mtc_delta = mtc + 256 - data->last_mtc;
		data->ctc_delta += mtc_delta << decoder->mtc_shift;
		data->last_mtc = mtc;

		if (decoder->tsc_ctc_mult) {
			timestamp = data->ctc_timestamp +
				data->ctc_delta * decoder->tsc_ctc_mult;
		} else {
			timestamp = data->ctc_timestamp +
				multdiv(data->ctc_delta,
					decoder->tsc_ctc_ratio_n,
					decoder->tsc_ctc_ratio_d);
		}

		if (timestamp < data->timestamp)
			return 1;

		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
			data->timestamp = timestamp;
			return 0;
		}

		break;

	case INTEL_PT_TSC:
714 715 716 717 718 719
		/*
		 * For now, do not support using TSC packets - refer
		 * intel_pt_calc_cyc_to_tsc().
		 */
		if (data->from_mtc)
			return 1;
720 721 722 723 724
		timestamp = pkt_info->packet.payload |
			    (data->timestamp & (0xffULL << 56));
		if (data->from_mtc && timestamp < data->timestamp &&
		    data->timestamp - timestamp < decoder->tsc_slip)
			return 1;
725
		if (timestamp < data->timestamp)
726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
			timestamp += (1ULL << 56);
		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
			if (data->from_mtc)
				return 1;
			data->tsc_timestamp = timestamp;
			data->timestamp = timestamp;
			return 0;
		}
		break;

	case INTEL_PT_TMA:
		if (data->from_mtc)
			return 1;

		if (!decoder->tsc_ctc_ratio_d)
			return 0;

		ctc = pkt_info->packet.payload;
		fc = pkt_info->packet.count;
		ctc_rem = ctc & decoder->ctc_rem_mask;

		data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;

		data->ctc_timestamp = data->tsc_timestamp - fc;
		if (decoder->tsc_ctc_mult) {
			data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
		} else {
			data->ctc_timestamp -=
				multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
					decoder->tsc_ctc_ratio_d);
		}

		data->ctc_delta = 0;
		data->have_tma = true;
760
		data->fixup_last_mtc = true;
761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777

		return 0;

	case INTEL_PT_CYC:
		data->cycle_cnt += pkt_info->packet.payload;
		return 0;

	case INTEL_PT_CBR:
		cbr = pkt_info->packet.payload;
		if (data->cbr && data->cbr != cbr)
			return 1;
		data->cbr = cbr;
		data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
		return 0;

	case INTEL_PT_TIP_PGD:
	case INTEL_PT_TRACESTOP:
778 779 780 781 782
	case INTEL_PT_EXSTOP:
	case INTEL_PT_EXSTOP_IP:
	case INTEL_PT_MWAIT:
	case INTEL_PT_PWRE:
	case INTEL_PT_PWRX:
783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831
	case INTEL_PT_OVF:
	case INTEL_PT_BAD: /* Does not happen */
	default:
		return 1;
	}

	if (!data->cbr && decoder->cbr) {
		data->cbr = decoder->cbr;
		data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
	}

	if (!data->cycle_cnt)
		return 1;

	cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;

	if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
	    cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
		return 1;
	}

	decoder->calc_cyc_to_tsc = cyc_to_tsc;
	decoder->have_calc_cyc_to_tsc = true;

	if (data->cbr) {
		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
	} else {
		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
			     cyc_to_tsc, pkt_info->pos);
	}

	return 1;
}

static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
				     bool from_mtc)
{
	struct intel_pt_calc_cyc_to_tsc_info data = {
		.cycle_cnt      = 0,
		.cbr            = 0,
		.last_mtc       = decoder->last_mtc,
		.ctc_timestamp  = decoder->ctc_timestamp,
		.ctc_delta      = decoder->ctc_delta,
		.tsc_timestamp  = decoder->tsc_timestamp,
		.timestamp      = decoder->timestamp,
		.have_tma       = decoder->have_tma,
832
		.fixup_last_mtc = decoder->fixup_last_mtc,
833 834 835 836
		.from_mtc       = from_mtc,
		.cbr_cyc_to_tsc = 0,
	};

837 838 839 840 841 842 843 844
	/*
	 * For now, do not support using TSC packets for at least the reasons:
	 * 1) timing might have stopped
	 * 2) TSC packets within PSB+ can slip against CYC packets
	 */
	if (!from_mtc)
		return;

845 846 847
	intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
}

A
Adrian Hunter 已提交
848 849 850 851
static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
{
	int ret;

852 853
	decoder->last_packet_type = decoder->packet.type;

A
Adrian Hunter 已提交
854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890
	do {
		decoder->pos += decoder->pkt_step;
		decoder->buf += decoder->pkt_step;
		decoder->len -= decoder->pkt_step;

		if (!decoder->len) {
			ret = intel_pt_get_next_data(decoder);
			if (ret)
				return ret;
		}

		ret = intel_pt_get_packet(decoder->buf, decoder->len,
					  &decoder->packet);
		if (ret == INTEL_PT_NEED_MORE_BYTES &&
		    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
			ret = intel_pt_get_split_packet(decoder);
			if (ret < 0)
				return ret;
		}
		if (ret <= 0)
			return intel_pt_bad_packet(decoder);

		decoder->pkt_len = ret;
		decoder->pkt_step = ret;
		intel_pt_decoder_log_packet(decoder);
	} while (decoder->packet.type == INTEL_PT_PAD);

	return 0;
}

static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp, masked_timestamp;

	timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
	masked_timestamp = timestamp & decoder->period_mask;
	if (decoder->continuous_period) {
891
		if (masked_timestamp > decoder->last_masked_timestamp)
A
Adrian Hunter 已提交
892 893 894 895
			return 1;
	} else {
		timestamp += 1;
		masked_timestamp = timestamp & decoder->period_mask;
896
		if (masked_timestamp > decoder->last_masked_timestamp) {
A
Adrian Hunter 已提交
897 898 899 900
			decoder->last_masked_timestamp = masked_timestamp;
			decoder->continuous_period = true;
		}
	}
901 902 903 904

	if (masked_timestamp < decoder->last_masked_timestamp)
		return decoder->period_ticks;

A
Adrian Hunter 已提交
905 906 907 908 909 910 911 912 913 914 915
	return decoder->period_ticks - (timestamp - masked_timestamp);
}

static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
{
	switch (decoder->period_type) {
	case INTEL_PT_PERIOD_INSTRUCTIONS:
		return decoder->period - decoder->period_insn_cnt;
	case INTEL_PT_PERIOD_TICKS:
		return intel_pt_next_period(decoder);
	case INTEL_PT_PERIOD_NONE:
916
	case INTEL_PT_PERIOD_MTC:
A
Adrian Hunter 已提交
917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932
	default:
		return 0;
	}
}

static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp, masked_timestamp;

	switch (decoder->period_type) {
	case INTEL_PT_PERIOD_INSTRUCTIONS:
		decoder->period_insn_cnt = 0;
		break;
	case INTEL_PT_PERIOD_TICKS:
		timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
		masked_timestamp = timestamp & decoder->period_mask;
933 934 935 936
		if (masked_timestamp > decoder->last_masked_timestamp)
			decoder->last_masked_timestamp = masked_timestamp;
		else
			decoder->last_masked_timestamp += decoder->period_ticks;
A
Adrian Hunter 已提交
937 938
		break;
	case INTEL_PT_PERIOD_NONE:
939
	case INTEL_PT_PERIOD_MTC:
A
Adrian Hunter 已提交
940 941 942 943 944 945 946 947 948 949 950 951 952
	default:
		break;
	}

	decoder->state.type |= INTEL_PT_INSTRUCTION;
}

static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
			      struct intel_pt_insn *intel_pt_insn, uint64_t ip)
{
	uint64_t max_insn_cnt, insn_cnt = 0;
	int err;

953 954 955
	if (!decoder->mtc_insn)
		decoder->mtc_insn = true;

A
Adrian Hunter 已提交
956 957 958 959 960
	max_insn_cnt = intel_pt_next_sample(decoder);

	err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
				 max_insn_cnt, decoder->data);

961
	decoder->tot_insn_cnt += insn_cnt;
A
Adrian Hunter 已提交
962
	decoder->timestamp_insn_cnt += insn_cnt;
963
	decoder->sample_insn_cnt += insn_cnt;
A
Adrian Hunter 已提交
964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
	decoder->period_insn_cnt += insn_cnt;

	if (err) {
		decoder->no_progress = 0;
		decoder->pkt_state = INTEL_PT_STATE_ERR2;
		intel_pt_log_at("ERROR: Failed to get instruction",
				decoder->ip);
		if (err == -ENOENT)
			return -ENOLINK;
		return -EILSEQ;
	}

	if (ip && decoder->ip == ip) {
		err = -EAGAIN;
		goto out;
	}

	if (max_insn_cnt && insn_cnt >= max_insn_cnt)
		intel_pt_sample_insn(decoder);

	if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
		decoder->state.type = INTEL_PT_INSTRUCTION;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		decoder->ip += intel_pt_insn->length;
		err = INTEL_PT_RETURN;
		goto out;
	}

	if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
		/* Zero-length calls are excluded */
		if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
		    intel_pt_insn->rel) {
			err = intel_pt_push(&decoder->stack, decoder->ip +
					    intel_pt_insn->length);
			if (err)
				goto out;
		}
	} else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
		decoder->ret_addr = intel_pt_pop(&decoder->stack);
	}

	if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
		int cnt = decoder->no_progress++;

		decoder->state.from_ip = decoder->ip;
		decoder->ip += intel_pt_insn->length +
				intel_pt_insn->rel;
		decoder->state.to_ip = decoder->ip;
		err = INTEL_PT_RETURN;

		/*
		 * Check for being stuck in a loop.  This can happen if a
		 * decoder error results in the decoder erroneously setting the
		 * ip to an address that is itself in an infinite loop that
		 * consumes no packets.  When that happens, there must be an
		 * unconditional branch.
		 */
		if (cnt) {
			if (cnt == 1) {
				decoder->stuck_ip = decoder->state.to_ip;
				decoder->stuck_ip_prd = 1;
				decoder->stuck_ip_cnt = 1;
			} else if (cnt > INTEL_PT_MAX_LOOPS ||
				   decoder->state.to_ip == decoder->stuck_ip) {
				intel_pt_log_at("ERROR: Never-ending loop",
						decoder->state.to_ip);
				decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
				err = -ELOOP;
				goto out;
			} else if (!--decoder->stuck_ip_cnt) {
				decoder->stuck_ip_prd += 1;
				decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
				decoder->stuck_ip = decoder->state.to_ip;
			}
		}
		goto out_no_progress;
	}
out:
	decoder->no_progress = 0;
out_no_progress:
	decoder->state.insn_op = intel_pt_insn->op;
	decoder->state.insn_len = intel_pt_insn->length;
1047 1048
	memcpy(decoder->state.insn, intel_pt_insn->buf,
	       INTEL_PT_INSN_BUF_SZ);
A
Adrian Hunter 已提交
1049 1050 1051 1052 1053 1054 1055

	if (decoder->tx_flags & INTEL_PT_IN_TX)
		decoder->state.flags |= INTEL_PT_IN_TX;

	return err;
}

1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106
static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
{
	bool ret = false;

	if (decoder->set_fup_tx_flags) {
		decoder->set_fup_tx_flags = false;
		decoder->tx_flags = decoder->fup_tx_flags;
		decoder->state.type = INTEL_PT_TRANSACTION;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		decoder->state.flags = decoder->fup_tx_flags;
		return true;
	}
	if (decoder->set_fup_ptw) {
		decoder->set_fup_ptw = false;
		decoder->state.type = INTEL_PT_PTW;
		decoder->state.flags |= INTEL_PT_FUP_IP;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		decoder->state.ptw_payload = decoder->fup_ptw_payload;
		return true;
	}
	if (decoder->set_fup_mwait) {
		decoder->set_fup_mwait = false;
		decoder->state.type = INTEL_PT_MWAIT_OP;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		decoder->state.mwait_payload = decoder->fup_mwait_payload;
		ret = true;
	}
	if (decoder->set_fup_pwre) {
		decoder->set_fup_pwre = false;
		decoder->state.type |= INTEL_PT_PWR_ENTRY;
		decoder->state.type &= ~INTEL_PT_BRANCH;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		decoder->state.pwre_payload = decoder->fup_pwre_payload;
		ret = true;
	}
	if (decoder->set_fup_exstop) {
		decoder->set_fup_exstop = false;
		decoder->state.type |= INTEL_PT_EX_STOP;
		decoder->state.type &= ~INTEL_PT_BRANCH;
		decoder->state.flags |= INTEL_PT_FUP_IP;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		ret = true;
	}
	return ret;
}

1107 1108 1109 1110 1111 1112 1113 1114 1115
static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
					  struct intel_pt_insn *intel_pt_insn,
					  uint64_t ip, int err)
{
	return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
	       intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
	       ip == decoder->ip + intel_pt_insn->length;
}

A
Adrian Hunter 已提交
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
{
	struct intel_pt_insn intel_pt_insn;
	uint64_t ip;
	int err;

	ip = decoder->last_ip;

	while (1) {
		err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
		if (err == INTEL_PT_RETURN)
			return 0;
1128 1129
		if (err == -EAGAIN ||
		    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1130
			if (intel_pt_fup_event(decoder))
A
Adrian Hunter 已提交
1131
				return 0;
1132
			return -EAGAIN;
A
Adrian Hunter 已提交
1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
		}
		decoder->set_fup_tx_flags = false;
		if (err)
			return err;

		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
			intel_pt_log_at("ERROR: Unexpected indirect branch",
					decoder->ip);
			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
			return -ENOENT;
		}

		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
			intel_pt_log_at("ERROR: Unexpected conditional branch",
					decoder->ip);
			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
			return -ENOENT;
		}

		intel_pt_bug(decoder);
	}
}

static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
{
	struct intel_pt_insn intel_pt_insn;
	int err;

	err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174
	if (err == INTEL_PT_RETURN &&
	    decoder->pgd_ip &&
	    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
	    (decoder->state.type & INTEL_PT_BRANCH) &&
	    decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
		/* Unconditional branch leaving filter region */
		decoder->no_progress = 0;
		decoder->pge = false;
		decoder->continuous_period = false;
		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
		decoder->state.to_ip = 0;
		return 0;
	}
A
Adrian Hunter 已提交
1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
	if (err == INTEL_PT_RETURN)
		return 0;
	if (err)
		return err;

	if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
		if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
			decoder->pge = false;
			decoder->continuous_period = false;
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			if (decoder->packet.count != 0)
				decoder->ip = decoder->last_ip;
		} else {
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			decoder->state.from_ip = decoder->ip;
			if (decoder->packet.count == 0) {
				decoder->state.to_ip = 0;
			} else {
				decoder->state.to_ip = decoder->last_ip;
				decoder->ip = decoder->last_ip;
			}
		}
		return 0;
	}

	if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
		uint64_t to_ip = decoder->ip + intel_pt_insn.length +
				 intel_pt_insn.rel;

		if (decoder->pgd_ip &&
		    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
		    decoder->pgd_ip(to_ip, decoder->data)) {
			/* Conditional branch leaving filter region */
			decoder->pge = false;
			decoder->continuous_period = false;
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			decoder->ip = to_ip;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			return 0;
		}
A
Adrian Hunter 已提交
1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346
		intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
				decoder->ip);
		decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
		return -ENOENT;
	}

	return intel_pt_bug(decoder);
}

static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
{
	struct intel_pt_insn intel_pt_insn;
	int err;

	while (1) {
		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
		if (err == INTEL_PT_RETURN)
			return 0;
		if (err)
			return err;

		if (intel_pt_insn.op == INTEL_PT_OP_RET) {
			if (!decoder->return_compression) {
				intel_pt_log_at("ERROR: RET when expecting conditional branch",
						decoder->ip);
				decoder->pkt_state = INTEL_PT_STATE_ERR3;
				return -ENOENT;
			}
			if (!decoder->ret_addr) {
				intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
						decoder->ip);
				decoder->pkt_state = INTEL_PT_STATE_ERR3;
				return -ENOENT;
			}
			if (!(decoder->tnt.payload & BIT63)) {
				intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
						decoder->ip);
				decoder->pkt_state = INTEL_PT_STATE_ERR3;
				return -ENOENT;
			}
			decoder->tnt.count -= 1;
			if (!decoder->tnt.count)
				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			decoder->tnt.payload <<= 1;
			decoder->state.from_ip = decoder->ip;
			decoder->ip = decoder->ret_addr;
			decoder->state.to_ip = decoder->ip;
			return 0;
		}

		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
			/* Handle deferred TIPs */
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type != INTEL_PT_TIP ||
			    decoder->packet.count == 0) {
				intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
						decoder->ip);
				decoder->pkt_state = INTEL_PT_STATE_ERR3;
				decoder->pkt_step = 0;
				return -ENOENT;
			}
			intel_pt_set_last_ip(decoder);
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = decoder->last_ip;
			decoder->ip = decoder->last_ip;
			return 0;
		}

		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
			decoder->tnt.count -= 1;
			if (!decoder->tnt.count)
				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			if (decoder->tnt.payload & BIT63) {
				decoder->tnt.payload <<= 1;
				decoder->state.from_ip = decoder->ip;
				decoder->ip += intel_pt_insn.length +
					       intel_pt_insn.rel;
				decoder->state.to_ip = decoder->ip;
				return 0;
			}
			/* Instruction sample for a non-taken branch */
			if (decoder->state.type & INTEL_PT_INSTRUCTION) {
				decoder->tnt.payload <<= 1;
				decoder->state.type = INTEL_PT_INSTRUCTION;
				decoder->state.from_ip = decoder->ip;
				decoder->state.to_ip = 0;
				decoder->ip += intel_pt_insn.length;
				return 0;
			}
			decoder->ip += intel_pt_insn.length;
			if (!decoder->tnt.count)
				return -EAGAIN;
			decoder->tnt.payload <<= 1;
			continue;
		}

		return intel_pt_bug(decoder);
	}
}

static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
{
	unsigned int fup_tx_flags;
	int err;

	fup_tx_flags = decoder->packet.payload &
		       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
	err = intel_pt_get_next_packet(decoder);
	if (err)
		return err;
	if (decoder->packet.type == INTEL_PT_FUP) {
		decoder->fup_tx_flags = fup_tx_flags;
		decoder->set_fup_tx_flags = true;
		if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
			*no_tip = true;
	} else {
		intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
				decoder->pos);
		intel_pt_update_in_tx(decoder);
	}
	return 0;
}

static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp;

1347 1348
	decoder->have_tma = false;

A
Adrian Hunter 已提交
1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365
	if (decoder->ref_timestamp) {
		timestamp = decoder->packet.payload |
			    (decoder->ref_timestamp & (0xffULL << 56));
		if (timestamp < decoder->ref_timestamp) {
			if (decoder->ref_timestamp - timestamp > (1ULL << 55))
				timestamp += (1ULL << 56);
		} else {
			if (timestamp - decoder->ref_timestamp > (1ULL << 55))
				timestamp -= (1ULL << 56);
		}
		decoder->tsc_timestamp = timestamp;
		decoder->timestamp = timestamp;
		decoder->ref_timestamp = 0;
		decoder->timestamp_insn_cnt = 0;
	} else if (decoder->timestamp) {
		timestamp = decoder->packet.payload |
			    (decoder->timestamp & (0xffULL << 56));
1366
		decoder->tsc_timestamp = timestamp;
A
Adrian Hunter 已提交
1367
		if (timestamp < decoder->timestamp &&
1368 1369
		    decoder->timestamp - timestamp < decoder->tsc_slip) {
			intel_pt_log_to("Suppressing backwards timestamp",
A
Adrian Hunter 已提交
1370 1371 1372
					timestamp);
			timestamp = decoder->timestamp;
		}
1373
		if (timestamp < decoder->timestamp) {
A
Adrian Hunter 已提交
1374 1375
			intel_pt_log_to("Wraparound timestamp", timestamp);
			timestamp += (1ULL << 56);
1376
			decoder->tsc_timestamp = timestamp;
A
Adrian Hunter 已提交
1377 1378 1379 1380 1381
		}
		decoder->timestamp = timestamp;
		decoder->timestamp_insn_cnt = 0;
	}

1382 1383 1384 1385 1386 1387 1388
	if (decoder->last_packet_type == INTEL_PT_CYC) {
		decoder->cyc_ref_timestamp = decoder->timestamp;
		decoder->cycle_cnt = 0;
		decoder->have_calc_cyc_to_tsc = false;
		intel_pt_calc_cyc_to_tsc(decoder, false);
	}

A
Adrian Hunter 已提交
1389 1390 1391 1392 1393 1394 1395
	intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

static int intel_pt_overflow(struct intel_pt_decoder *decoder)
{
	intel_pt_log("ERROR: Buffer overflow\n");
	intel_pt_clear_tx_flags(decoder);
1396
	decoder->timestamp_insn_cnt = 0;
A
Adrian Hunter 已提交
1397 1398 1399 1400 1401
	decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
	decoder->overflow = true;
	return -EOVERFLOW;
}

1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
{
	uint32_t ctc = decoder->packet.payload;
	uint32_t fc = decoder->packet.count;
	uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;

	if (!decoder->tsc_ctc_ratio_d)
		return;

	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
	decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
	if (decoder->tsc_ctc_mult) {
		decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
	} else {
		decoder->ctc_timestamp -= multdiv(ctc_rem,
						  decoder->tsc_ctc_ratio_n,
						  decoder->tsc_ctc_ratio_d);
	}
	decoder->ctc_delta = 0;
	decoder->have_tma = true;
1422
	decoder->fixup_last_mtc = true;
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
}

static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp;
	uint32_t mtc, mtc_delta;

	if (!decoder->have_tma)
		return;

	mtc = decoder->packet.payload;

1437 1438 1439 1440 1441 1442
	if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
		decoder->fixup_last_mtc = false;
		intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
					&decoder->last_mtc);
	}

1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
	if (mtc > decoder->last_mtc)
		mtc_delta = mtc - decoder->last_mtc;
	else
		mtc_delta = mtc + 256 - decoder->last_mtc;

	decoder->ctc_delta += mtc_delta << decoder->mtc_shift;

	if (decoder->tsc_ctc_mult) {
		timestamp = decoder->ctc_timestamp +
			    decoder->ctc_delta * decoder->tsc_ctc_mult;
	} else {
		timestamp = decoder->ctc_timestamp +
			    multdiv(decoder->ctc_delta,
				    decoder->tsc_ctc_ratio_n,
				    decoder->tsc_ctc_ratio_d);
	}

	if (timestamp < decoder->timestamp)
		intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
			     timestamp, decoder->timestamp);
	else
		decoder->timestamp = timestamp;

	decoder->timestamp_insn_cnt = 0;
	decoder->last_mtc = mtc;
1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478

	if (decoder->last_packet_type == INTEL_PT_CYC) {
		decoder->cyc_ref_timestamp = decoder->timestamp;
		decoder->cycle_cnt = 0;
		decoder->have_calc_cyc_to_tsc = false;
		intel_pt_calc_cyc_to_tsc(decoder, true);
	}
}

static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
{
1479
	unsigned int cbr = decoder->packet.payload & 0xff;
1480

1481 1482
	decoder->cbr_payload = decoder->packet.payload;

1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512
	if (decoder->cbr == cbr)
		return;

	decoder->cbr = cbr;
	decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
}

static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp = decoder->cyc_ref_timestamp;

	decoder->have_cyc = true;

	decoder->cycle_cnt += decoder->packet.payload;

	if (!decoder->cyc_ref_timestamp)
		return;

	if (decoder->have_calc_cyc_to_tsc)
		timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
	else if (decoder->cbr)
		timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
	else
		return;

	if (timestamp < decoder->timestamp)
		intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
			     timestamp, decoder->timestamp);
	else
		decoder->timestamp = timestamp;
1513 1514

	decoder->timestamp_insn_cnt = 0;
1515 1516
}

A
Adrian Hunter 已提交
1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534
/* Walk PSB+ packets when already in sync. */
static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
{
	int err;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;

		switch (decoder->packet.type) {
		case INTEL_PT_PSBEND:
			return 0;

		case INTEL_PT_TIP_PGD:
		case INTEL_PT_TIP_PGE:
		case INTEL_PT_TIP:
		case INTEL_PT_TNT:
1535
		case INTEL_PT_TRACESTOP:
A
Adrian Hunter 已提交
1536 1537
		case INTEL_PT_BAD:
		case INTEL_PT_PSB:
1538 1539 1540 1541 1542 1543 1544
		case INTEL_PT_PTWRITE:
		case INTEL_PT_PTWRITE_IP:
		case INTEL_PT_EXSTOP:
		case INTEL_PT_EXSTOP_IP:
		case INTEL_PT_MWAIT:
		case INTEL_PT_PWRE:
		case INTEL_PT_PWRX:
1545
			decoder->have_tma = false;
A
Adrian Hunter 已提交
1546 1547 1548 1549 1550 1551 1552 1553 1554 1555
			intel_pt_log("ERROR: Unexpected packet\n");
			return -EAGAIN;

		case INTEL_PT_OVF:
			return intel_pt_overflow(decoder);

		case INTEL_PT_TSC:
			intel_pt_calc_tsc_timestamp(decoder);
			break;

1556
		case INTEL_PT_TMA:
1557
			intel_pt_calc_tma(decoder);
1558 1559
			break;

A
Adrian Hunter 已提交
1560
		case INTEL_PT_CBR:
1561
			intel_pt_calc_cbr(decoder);
A
Adrian Hunter 已提交
1562 1563 1564 1565 1566 1567 1568
			break;

		case INTEL_PT_MODE_EXEC:
			decoder->exec_mode = decoder->packet.payload;
			break;

		case INTEL_PT_PIP:
1569
			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
A
Adrian Hunter 已提交
1570 1571 1572 1573
			break;

		case INTEL_PT_FUP:
			decoder->pge = true;
1574 1575
			if (decoder->packet.count)
				intel_pt_set_last_ip(decoder);
A
Adrian Hunter 已提交
1576 1577 1578 1579 1580 1581
			break;

		case INTEL_PT_MODE_TSX:
			intel_pt_update_in_tx(decoder);
			break;

1582
		case INTEL_PT_MTC:
1583 1584 1585
			intel_pt_calc_mtc_timestamp(decoder);
			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
				decoder->state.type |= INTEL_PT_INSTRUCTION;
1586 1587 1588 1589 1590
			break;

		case INTEL_PT_CYC:
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
A
Adrian Hunter 已提交
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617
		case INTEL_PT_PAD:
		default:
			break;
		}
	}
}

static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
{
	int err;

	if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
		decoder->tx_flags = 0;
		decoder->state.flags &= ~INTEL_PT_IN_TX;
		decoder->state.flags |= INTEL_PT_ABORT_TX;
	} else {
		decoder->state.flags |= INTEL_PT_ASYNC;
	}

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;

		switch (decoder->packet.type) {
		case INTEL_PT_TNT:
		case INTEL_PT_FUP:
1618
		case INTEL_PT_TRACESTOP:
A
Adrian Hunter 已提交
1619 1620
		case INTEL_PT_PSB:
		case INTEL_PT_TSC:
1621
		case INTEL_PT_TMA:
A
Adrian Hunter 已提交
1622 1623 1624
		case INTEL_PT_MODE_TSX:
		case INTEL_PT_BAD:
		case INTEL_PT_PSBEND:
1625 1626 1627 1628 1629 1630 1631
		case INTEL_PT_PTWRITE:
		case INTEL_PT_PTWRITE_IP:
		case INTEL_PT_EXSTOP:
		case INTEL_PT_EXSTOP_IP:
		case INTEL_PT_MWAIT:
		case INTEL_PT_PWRE:
		case INTEL_PT_PWRX:
A
Adrian Hunter 已提交
1632 1633
			intel_pt_log("ERROR: Missing TIP after FUP\n");
			decoder->pkt_state = INTEL_PT_STATE_ERR3;
1634
			decoder->pkt_step = 0;
A
Adrian Hunter 已提交
1635 1636
			return -ENOENT;

1637 1638 1639 1640
		case INTEL_PT_CBR:
			intel_pt_calc_cbr(decoder);
			break;

A
Adrian Hunter 已提交
1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
		case INTEL_PT_OVF:
			return intel_pt_overflow(decoder);

		case INTEL_PT_TIP_PGD:
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			if (decoder->packet.count != 0) {
				intel_pt_set_ip(decoder);
				intel_pt_log("Omitting PGD ip " x64_fmt "\n",
					     decoder->ip);
			}
			decoder->pge = false;
			decoder->continuous_period = false;
			return 0;

		case INTEL_PT_TIP_PGE:
			decoder->pge = true;
			intel_pt_log("Omitting PGE ip " x64_fmt "\n",
				     decoder->ip);
			decoder->state.from_ip = 0;
			if (decoder->packet.count == 0) {
				decoder->state.to_ip = 0;
			} else {
				intel_pt_set_ip(decoder);
				decoder->state.to_ip = decoder->ip;
			}
			return 0;

		case INTEL_PT_TIP:
			decoder->state.from_ip = decoder->ip;
			if (decoder->packet.count == 0) {
				decoder->state.to_ip = 0;
			} else {
				intel_pt_set_ip(decoder);
				decoder->state.to_ip = decoder->ip;
			}
			return 0;

		case INTEL_PT_PIP:
1680 1681 1682 1683
			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
			break;

		case INTEL_PT_MTC:
1684 1685 1686
			intel_pt_calc_mtc_timestamp(decoder);
			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
				decoder->state.type |= INTEL_PT_INSTRUCTION;
1687 1688 1689
			break;

		case INTEL_PT_CYC:
1690
			intel_pt_calc_cyc_timestamp(decoder);
A
Adrian Hunter 已提交
1691 1692 1693 1694 1695 1696
			break;

		case INTEL_PT_MODE_EXEC:
			decoder->exec_mode = decoder->packet.payload;
			break;

1697 1698
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
A
Adrian Hunter 已提交
1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764
		case INTEL_PT_PAD:
			break;

		default:
			return intel_pt_bug(decoder);
		}
	}
}

static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
{
	bool no_tip = false;
	int err;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;
next:
		switch (decoder->packet.type) {
		case INTEL_PT_TNT:
			if (!decoder->packet.count)
				break;
			decoder->tnt = decoder->packet;
			decoder->pkt_state = INTEL_PT_STATE_TNT;
			err = intel_pt_walk_tnt(decoder);
			if (err == -EAGAIN)
				break;
			return err;

		case INTEL_PT_TIP_PGD:
			if (decoder->packet.count != 0)
				intel_pt_set_last_ip(decoder);
			decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
			return intel_pt_walk_tip(decoder);

		case INTEL_PT_TIP_PGE: {
			decoder->pge = true;
			if (decoder->packet.count == 0) {
				intel_pt_log_at("Skipping zero TIP.PGE",
						decoder->pos);
				break;
			}
			intel_pt_set_ip(decoder);
			decoder->state.from_ip = 0;
			decoder->state.to_ip = decoder->ip;
			return 0;
		}

		case INTEL_PT_OVF:
			return intel_pt_overflow(decoder);

		case INTEL_PT_TIP:
			if (decoder->packet.count != 0)
				intel_pt_set_last_ip(decoder);
			decoder->pkt_state = INTEL_PT_STATE_TIP;
			return intel_pt_walk_tip(decoder);

		case INTEL_PT_FUP:
			if (decoder->packet.count == 0) {
				intel_pt_log_at("Skipping zero FUP",
						decoder->pos);
				no_tip = false;
				break;
			}
			intel_pt_set_last_ip(decoder);
1765 1766
			if (!decoder->branch_enable) {
				decoder->ip = decoder->last_ip;
1767 1768 1769
				if (intel_pt_fup_event(decoder))
					return 0;
				no_tip = false;
1770 1771
				break;
			}
1772 1773
			if (decoder->set_fup_mwait)
				no_tip = true;
A
Adrian Hunter 已提交
1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790
			err = intel_pt_walk_fup(decoder);
			if (err != -EAGAIN) {
				if (err)
					return err;
				if (no_tip)
					decoder->pkt_state =
						INTEL_PT_STATE_FUP_NO_TIP;
				else
					decoder->pkt_state = INTEL_PT_STATE_FUP;
				return 0;
			}
			if (no_tip) {
				no_tip = false;
				break;
			}
			return intel_pt_walk_fup_tip(decoder);

1791
		case INTEL_PT_TRACESTOP:
1792 1793 1794 1795
			decoder->pge = false;
			decoder->continuous_period = false;
			intel_pt_clear_tx_flags(decoder);
			decoder->have_tma = false;
1796 1797
			break;

A
Adrian Hunter 已提交
1798
		case INTEL_PT_PSB:
A
Adrian Hunter 已提交
1799 1800
			decoder->last_ip = 0;
			decoder->have_last_ip = true;
A
Adrian Hunter 已提交
1801 1802 1803 1804 1805 1806 1807 1808 1809
			intel_pt_clear_stack(&decoder->stack);
			err = intel_pt_walk_psbend(decoder);
			if (err == -EAGAIN)
				goto next;
			if (err)
				return err;
			break;

		case INTEL_PT_PIP:
1810 1811 1812 1813
			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
			break;

		case INTEL_PT_MTC:
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
			intel_pt_calc_mtc_timestamp(decoder);
			if (decoder->period_type != INTEL_PT_PERIOD_MTC)
				break;
			/*
			 * Ensure that there has been an instruction since the
			 * last MTC.
			 */
			if (!decoder->mtc_insn)
				break;
			decoder->mtc_insn = false;
			/* Ensure that there is a timestamp */
			if (!decoder->timestamp)
				break;
			decoder->state.type = INTEL_PT_INSTRUCTION;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			decoder->mtc_insn = false;
			return 0;
A
Adrian Hunter 已提交
1832 1833 1834 1835 1836

		case INTEL_PT_TSC:
			intel_pt_calc_tsc_timestamp(decoder);
			break;

1837
		case INTEL_PT_TMA:
1838
			intel_pt_calc_tma(decoder);
1839 1840 1841
			break;

		case INTEL_PT_CYC:
1842
			intel_pt_calc_cyc_timestamp(decoder);
1843 1844
			break;

A
Adrian Hunter 已提交
1845
		case INTEL_PT_CBR:
1846
			intel_pt_calc_cbr(decoder);
1847 1848 1849 1850 1851 1852 1853 1854 1855 1856
			if (!decoder->branch_enable &&
			    decoder->cbr != decoder->cbr_seen) {
				decoder->cbr_seen = decoder->cbr;
				decoder->state.type = INTEL_PT_CBR_CHG;
				decoder->state.from_ip = decoder->ip;
				decoder->state.to_ip = 0;
				decoder->state.cbr_payload =
							decoder->packet.payload;
				return 0;
			}
A
Adrian Hunter 已提交
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
			break;

		case INTEL_PT_MODE_EXEC:
			decoder->exec_mode = decoder->packet.payload;
			break;

		case INTEL_PT_MODE_TSX:
			/* MODE_TSX need not be followed by FUP */
			if (!decoder->pge) {
				intel_pt_update_in_tx(decoder);
				break;
			}
			err = intel_pt_mode_tsx(decoder, &no_tip);
			if (err)
				return err;
			goto next;

		case INTEL_PT_BAD: /* Does not happen */
			return intel_pt_bug(decoder);

		case INTEL_PT_PSBEND:
1878 1879
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
A
Adrian Hunter 已提交
1880 1881 1882
		case INTEL_PT_PAD:
			break;

1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947
		case INTEL_PT_PTWRITE_IP:
			decoder->fup_ptw_payload = decoder->packet.payload;
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type == INTEL_PT_FUP) {
				decoder->set_fup_ptw = true;
				no_tip = true;
			} else {
				intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
						decoder->pos);
			}
			goto next;

		case INTEL_PT_PTWRITE:
			decoder->state.type = INTEL_PT_PTW;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			decoder->state.ptw_payload = decoder->packet.payload;
			return 0;

		case INTEL_PT_MWAIT:
			decoder->fup_mwait_payload = decoder->packet.payload;
			decoder->set_fup_mwait = true;
			break;

		case INTEL_PT_PWRE:
			if (decoder->set_fup_mwait) {
				decoder->fup_pwre_payload =
							decoder->packet.payload;
				decoder->set_fup_pwre = true;
				break;
			}
			decoder->state.type = INTEL_PT_PWR_ENTRY;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			decoder->state.pwrx_payload = decoder->packet.payload;
			return 0;

		case INTEL_PT_EXSTOP_IP:
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type == INTEL_PT_FUP) {
				decoder->set_fup_exstop = true;
				no_tip = true;
			} else {
				intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
						decoder->pos);
			}
			goto next;

		case INTEL_PT_EXSTOP:
			decoder->state.type = INTEL_PT_EX_STOP;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			return 0;

		case INTEL_PT_PWRX:
			decoder->state.type = INTEL_PT_PWR_EXIT;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			decoder->state.pwrx_payload = decoder->packet.payload;
			return 0;

A
Adrian Hunter 已提交
1948 1949 1950 1951 1952 1953
		default:
			return intel_pt_bug(decoder);
		}
	}
}

1954 1955
static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
{
1956 1957 1958
	return decoder->packet.count &&
	       (decoder->have_last_ip || decoder->packet.count == 3 ||
		decoder->packet.count == 6);
1959 1960
}

A
Adrian Hunter 已提交
1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
/* Walk PSB+ packets to get in sync. */
static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
{
	int err;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;

		switch (decoder->packet.type) {
		case INTEL_PT_TIP_PGD:
			decoder->continuous_period = false;
1974
			__fallthrough;
A
Adrian Hunter 已提交
1975 1976
		case INTEL_PT_TIP_PGE:
		case INTEL_PT_TIP:
1977 1978 1979 1980 1981 1982 1983
		case INTEL_PT_PTWRITE:
		case INTEL_PT_PTWRITE_IP:
		case INTEL_PT_EXSTOP:
		case INTEL_PT_EXSTOP_IP:
		case INTEL_PT_MWAIT:
		case INTEL_PT_PWRE:
		case INTEL_PT_PWRX:
A
Adrian Hunter 已提交
1984 1985 1986 1987 1988
			intel_pt_log("ERROR: Unexpected packet\n");
			return -ENOENT;

		case INTEL_PT_FUP:
			decoder->pge = true;
1989
			if (intel_pt_have_ip(decoder)) {
A
Adrian Hunter 已提交
1990 1991 1992 1993 1994 1995 1996 1997 1998
				uint64_t current_ip = decoder->ip;

				intel_pt_set_ip(decoder);
				if (current_ip)
					intel_pt_log_to("Setting IP",
							decoder->ip);
			}
			break;

1999
		case INTEL_PT_MTC:
2000
			intel_pt_calc_mtc_timestamp(decoder);
2001 2002
			break;

A
Adrian Hunter 已提交
2003 2004 2005 2006
		case INTEL_PT_TSC:
			intel_pt_calc_tsc_timestamp(decoder);
			break;

2007
		case INTEL_PT_TMA:
2008
			intel_pt_calc_tma(decoder);
2009 2010 2011
			break;

		case INTEL_PT_CYC:
2012
			intel_pt_calc_cyc_timestamp(decoder);
2013 2014
			break;

A
Adrian Hunter 已提交
2015
		case INTEL_PT_CBR:
2016
			intel_pt_calc_cbr(decoder);
A
Adrian Hunter 已提交
2017 2018 2019
			break;

		case INTEL_PT_PIP:
2020
			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
A
Adrian Hunter 已提交
2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
			break;

		case INTEL_PT_MODE_EXEC:
			decoder->exec_mode = decoder->packet.payload;
			break;

		case INTEL_PT_MODE_TSX:
			intel_pt_update_in_tx(decoder);
			break;

2031
		case INTEL_PT_TRACESTOP:
2032 2033 2034
			decoder->pge = false;
			decoder->continuous_period = false;
			intel_pt_clear_tx_flags(decoder);
2035 2036
			__fallthrough;

A
Adrian Hunter 已提交
2037
		case INTEL_PT_TNT:
2038
			decoder->have_tma = false;
A
Adrian Hunter 已提交
2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055
			intel_pt_log("ERROR: Unexpected packet\n");
			if (decoder->ip)
				decoder->pkt_state = INTEL_PT_STATE_ERR4;
			else
				decoder->pkt_state = INTEL_PT_STATE_ERR3;
			return -ENOENT;

		case INTEL_PT_BAD: /* Does not happen */
			return intel_pt_bug(decoder);

		case INTEL_PT_OVF:
			return intel_pt_overflow(decoder);

		case INTEL_PT_PSBEND:
			return 0;

		case INTEL_PT_PSB:
2056 2057
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
A
Adrian Hunter 已提交
2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076
		case INTEL_PT_PAD:
		default:
			break;
		}
	}
}

static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
{
	int err;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;

		switch (decoder->packet.type) {
		case INTEL_PT_TIP_PGD:
			decoder->continuous_period = false;
2077
			__fallthrough;
A
Adrian Hunter 已提交
2078 2079 2080
		case INTEL_PT_TIP_PGE:
		case INTEL_PT_TIP:
			decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
2081
			if (intel_pt_have_ip(decoder))
A
Adrian Hunter 已提交
2082 2083 2084 2085 2086 2087
				intel_pt_set_ip(decoder);
			if (decoder->ip)
				return 0;
			break;

		case INTEL_PT_FUP:
2088 2089 2090 2091
			if (intel_pt_have_ip(decoder))
				intel_pt_set_ip(decoder);
			if (decoder->ip)
				return 0;
A
Adrian Hunter 已提交
2092 2093
			break;

2094
		case INTEL_PT_MTC:
2095
			intel_pt_calc_mtc_timestamp(decoder);
2096 2097
			break;

A
Adrian Hunter 已提交
2098 2099 2100 2101
		case INTEL_PT_TSC:
			intel_pt_calc_tsc_timestamp(decoder);
			break;

2102
		case INTEL_PT_TMA:
2103
			intel_pt_calc_tma(decoder);
2104 2105 2106
			break;

		case INTEL_PT_CYC:
2107
			intel_pt_calc_cyc_timestamp(decoder);
2108 2109
			break;

A
Adrian Hunter 已提交
2110
		case INTEL_PT_CBR:
2111
			intel_pt_calc_cbr(decoder);
A
Adrian Hunter 已提交
2112 2113 2114
			break;

		case INTEL_PT_PIP:
2115
			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
A
Adrian Hunter 已提交
2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131
			break;

		case INTEL_PT_MODE_EXEC:
			decoder->exec_mode = decoder->packet.payload;
			break;

		case INTEL_PT_MODE_TSX:
			intel_pt_update_in_tx(decoder);
			break;

		case INTEL_PT_OVF:
			return intel_pt_overflow(decoder);

		case INTEL_PT_BAD: /* Does not happen */
			return intel_pt_bug(decoder);

2132
		case INTEL_PT_TRACESTOP:
2133 2134 2135 2136
			decoder->pge = false;
			decoder->continuous_period = false;
			intel_pt_clear_tx_flags(decoder);
			decoder->have_tma = false;
2137 2138
			break;

A
Adrian Hunter 已提交
2139
		case INTEL_PT_PSB:
A
Adrian Hunter 已提交
2140 2141
			decoder->last_ip = 0;
			decoder->have_last_ip = true;
2142
			intel_pt_clear_stack(&decoder->stack);
A
Adrian Hunter 已提交
2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154
			err = intel_pt_walk_psb(decoder);
			if (err)
				return err;
			if (decoder->ip) {
				/* Do not have a sample */
				decoder->state.type = 0;
				return 0;
			}
			break;

		case INTEL_PT_TNT:
		case INTEL_PT_PSBEND:
2155 2156
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
A
Adrian Hunter 已提交
2157
		case INTEL_PT_PAD:
2158 2159 2160 2161 2162 2163 2164
		case INTEL_PT_PTWRITE:
		case INTEL_PT_PTWRITE_IP:
		case INTEL_PT_EXSTOP:
		case INTEL_PT_EXSTOP_IP:
		case INTEL_PT_MWAIT:
		case INTEL_PT_PWRE:
		case INTEL_PT_PWRX:
A
Adrian Hunter 已提交
2165 2166 2167 2168 2169 2170 2171 2172 2173 2174
		default:
			break;
		}
	}
}

static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
{
	int err;

2175
	decoder->set_fup_tx_flags = false;
2176 2177 2178 2179
	decoder->set_fup_ptw = false;
	decoder->set_fup_mwait = false;
	decoder->set_fup_pwre = false;
	decoder->set_fup_exstop = false;
2180

2181 2182 2183 2184 2185 2186 2187
	if (!decoder->branch_enable) {
		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
		decoder->overflow = false;
		decoder->state.type = 0; /* Do not have a sample */
		return 0;
	}

A
Adrian Hunter 已提交
2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295
	intel_pt_log("Scanning for full IP\n");
	err = intel_pt_walk_to_ip(decoder);
	if (err)
		return err;

	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	decoder->overflow = false;

	decoder->state.from_ip = 0;
	decoder->state.to_ip = decoder->ip;
	intel_pt_log_to("Setting IP", decoder->ip);

	return 0;
}

static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
{
	const unsigned char *end = decoder->buf + decoder->len;
	size_t i;

	for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
		if (i > decoder->len)
			continue;
		if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
			return i;
	}
	return 0;
}

static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
{
	size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
	const char *psb = INTEL_PT_PSB_STR;

	if (rest_psb > decoder->len ||
	    memcmp(decoder->buf, psb + part_psb, rest_psb))
		return 0;

	return rest_psb;
}

static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
				  int part_psb)
{
	int rest_psb, ret;

	decoder->pos += decoder->len;
	decoder->len = 0;

	ret = intel_pt_get_next_data(decoder);
	if (ret)
		return ret;

	rest_psb = intel_pt_rest_psb(decoder, part_psb);
	if (!rest_psb)
		return 0;

	decoder->pos -= part_psb;
	decoder->next_buf = decoder->buf + rest_psb;
	decoder->next_len = decoder->len - rest_psb;
	memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
	decoder->buf = decoder->temp_buf;
	decoder->len = INTEL_PT_PSB_LEN;

	return 0;
}

static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
{
	unsigned char *next;
	int ret;

	intel_pt_log("Scanning for PSB\n");
	while (1) {
		if (!decoder->len) {
			ret = intel_pt_get_next_data(decoder);
			if (ret)
				return ret;
		}

		next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
			      INTEL_PT_PSB_LEN);
		if (!next) {
			int part_psb;

			part_psb = intel_pt_part_psb(decoder);
			if (part_psb) {
				ret = intel_pt_get_split_psb(decoder, part_psb);
				if (ret)
					return ret;
			} else {
				decoder->pos += decoder->len;
				decoder->len = 0;
			}
			continue;
		}

		decoder->pkt_step = next - decoder->buf;
		return intel_pt_get_next_packet(decoder);
	}
}

static int intel_pt_sync(struct intel_pt_decoder *decoder)
{
	int err;

	decoder->pge = false;
	decoder->continuous_period = false;
A
Adrian Hunter 已提交
2296
	decoder->have_last_ip = false;
A
Adrian Hunter 已提交
2297 2298 2299 2300 2301 2302 2303 2304
	decoder->last_ip = 0;
	decoder->ip = 0;
	intel_pt_clear_stack(&decoder->stack);

	err = intel_pt_scan_for_psb(decoder);
	if (err)
		return err;

A
Adrian Hunter 已提交
2305
	decoder->have_last_ip = true;
A
Adrian Hunter 已提交
2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323
	decoder->pkt_state = INTEL_PT_STATE_NO_IP;

	err = intel_pt_walk_psb(decoder);
	if (err)
		return err;

	if (decoder->ip) {
		decoder->state.type = 0; /* Do not have a sample */
		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	} else {
		return intel_pt_sync_ip(decoder);
	}

	return 0;
}

static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
{
2324
	uint64_t est = decoder->sample_insn_cnt << 1;
A
Adrian Hunter 已提交
2325 2326 2327 2328 2329 2330 2331

	if (!decoder->cbr || !decoder->max_non_turbo_ratio)
		goto out;

	est *= decoder->max_non_turbo_ratio;
	est /= decoder->cbr;
out:
2332
	return decoder->sample_timestamp + est;
A
Adrian Hunter 已提交
2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347
}

const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
{
	int err;

	do {
		decoder->state.type = INTEL_PT_BRANCH;
		decoder->state.flags = 0;

		switch (decoder->pkt_state) {
		case INTEL_PT_STATE_NO_PSB:
			err = intel_pt_sync(decoder);
			break;
		case INTEL_PT_STATE_NO_IP:
A
Adrian Hunter 已提交
2348
			decoder->have_last_ip = false;
A
Adrian Hunter 已提交
2349
			decoder->last_ip = 0;
2350
			decoder->ip = 0;
2351
			__fallthrough;
A
Adrian Hunter 已提交
2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386
		case INTEL_PT_STATE_ERR_RESYNC:
			err = intel_pt_sync_ip(decoder);
			break;
		case INTEL_PT_STATE_IN_SYNC:
			err = intel_pt_walk_trace(decoder);
			break;
		case INTEL_PT_STATE_TNT:
			err = intel_pt_walk_tnt(decoder);
			if (err == -EAGAIN)
				err = intel_pt_walk_trace(decoder);
			break;
		case INTEL_PT_STATE_TIP:
		case INTEL_PT_STATE_TIP_PGD:
			err = intel_pt_walk_tip(decoder);
			break;
		case INTEL_PT_STATE_FUP:
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			err = intel_pt_walk_fup(decoder);
			if (err == -EAGAIN)
				err = intel_pt_walk_fup_tip(decoder);
			else if (!err)
				decoder->pkt_state = INTEL_PT_STATE_FUP;
			break;
		case INTEL_PT_STATE_FUP_NO_TIP:
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			err = intel_pt_walk_fup(decoder);
			if (err == -EAGAIN)
				err = intel_pt_walk_trace(decoder);
			break;
		default:
			err = intel_pt_bug(decoder);
			break;
		}
	} while (err == -ENOLINK);

2387 2388 2389
	if (err) {
		decoder->state.err = intel_pt_ext_err(err);
		decoder->state.from_ip = decoder->ip;
2390 2391
		decoder->sample_timestamp = decoder->timestamp;
		decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
2392 2393
	} else {
		decoder->state.err = 0;
2394 2395 2396 2397 2398
		if (decoder->cbr != decoder->cbr_seen && decoder->state.type) {
			decoder->cbr_seen = decoder->cbr;
			decoder->state.type |= INTEL_PT_CBR_CHG;
			decoder->state.cbr_payload = decoder->cbr_payload;
		}
2399 2400 2401 2402
		if (intel_pt_sample_time(decoder->pkt_state)) {
			decoder->sample_timestamp = decoder->timestamp;
			decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
		}
2403 2404
	}

2405
	decoder->state.timestamp = decoder->sample_timestamp;
A
Adrian Hunter 已提交
2406 2407
	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
	decoder->state.cr3 = decoder->cr3;
2408
	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
A
Adrian Hunter 已提交
2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500

	return &decoder->state;
}

/**
 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
 * @buf: pointer to buffer pointer
 * @len: size of buffer
 *
 * Updates the buffer pointer to point to the start of the next PSB packet if
 * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
 * @len is adjusted accordingly.
 *
 * Return: %true if a PSB packet is found, %false otherwise.
 */
static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
{
	unsigned char *next;

	next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
	if (next) {
		*len -= next - *buf;
		*buf = next;
		return true;
	}
	return false;
}

/**
 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
 *                     packet.
 * @buf: pointer to buffer pointer
 * @len: size of buffer
 *
 * Updates the buffer pointer to point to the start of the following PSB packet
 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
 * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
 *
 * Return: %true if a PSB packet is found, %false otherwise.
 */
static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
{
	unsigned char *next;

	if (!*len)
		return false;

	next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
	if (next) {
		*len -= next - *buf;
		*buf = next;
		return true;
	}
	return false;
}

/**
 * intel_pt_last_psb - find the last PSB packet in a buffer.
 * @buf: buffer
 * @len: size of buffer
 *
 * This function finds the last PSB in a buffer.
 *
 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
 */
static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
{
	const char *n = INTEL_PT_PSB_STR;
	unsigned char *p;
	size_t k;

	if (len < INTEL_PT_PSB_LEN)
		return NULL;

	k = len - INTEL_PT_PSB_LEN + 1;
	while (1) {
		p = memrchr(buf, n[0], k);
		if (!p)
			return NULL;
		if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
			return p;
		k = p - buf;
		if (!k)
			return NULL;
	}
}

/**
 * intel_pt_next_tsc - find and return next TSC.
 * @buf: buffer
 * @len: size of buffer
 * @tsc: TSC value returned
2501
 * @rem: returns remaining size when TSC is found
A
Adrian Hunter 已提交
2502 2503 2504 2505 2506 2507 2508
 *
 * Find a TSC packet in @buf and return the TSC value.  This function assumes
 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
 * PSBEND packet is found.
 *
 * Return: %true if TSC is found, false otherwise.
 */
2509 2510
static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
			      size_t *rem)
A
Adrian Hunter 已提交
2511 2512 2513 2514 2515 2516 2517 2518 2519 2520
{
	struct intel_pt_pkt packet;
	int ret;

	while (len) {
		ret = intel_pt_get_packet(buf, len, &packet);
		if (ret <= 0)
			return false;
		if (packet.type == INTEL_PT_TSC) {
			*tsc = packet.payload;
2521
			*rem = len;
A
Adrian Hunter 已提交
2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564
			return true;
		}
		if (packet.type == INTEL_PT_PSBEND)
			return false;
		buf += ret;
		len -= ret;
	}
	return false;
}

/**
 * intel_pt_tsc_cmp - compare 7-byte TSCs.
 * @tsc1: first TSC to compare
 * @tsc2: second TSC to compare
 *
 * This function compares 7-byte TSC values allowing for the possibility that
 * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
 * around so for that purpose this function assumes the absolute difference is
 * less than half the maximum difference.
 *
 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
 * after @tsc2.
 */
static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
{
	const uint64_t halfway = (1ULL << 55);

	if (tsc1 == tsc2)
		return 0;

	if (tsc1 < tsc2) {
		if (tsc2 - tsc1 < halfway)
			return -1;
		else
			return 1;
	} else {
		if (tsc1 - tsc2 < halfway)
			return 1;
		else
			return -1;
	}
}

2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592
#define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)

/**
 * adj_for_padding - adjust overlap to account for padding.
 * @buf_b: second buffer
 * @buf_a: first buffer
 * @len_a: size of first buffer
 *
 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
 * accordingly.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts
 */
static unsigned char *adj_for_padding(unsigned char *buf_b,
				      unsigned char *buf_a, size_t len_a)
{
	unsigned char *p = buf_b - MAX_PADDING;
	unsigned char *q = buf_a + len_a - MAX_PADDING;
	int i;

	for (i = MAX_PADDING; i; i--, p++, q++) {
		if (*p != *q)
			break;
	}

	return p;
}

A
Adrian Hunter 已提交
2593 2594 2595 2596 2597 2598 2599
/**
 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
 *                             using TSC.
 * @buf_a: first buffer
 * @len_a: size of first buffer
 * @buf_b: second buffer
 * @len_b: size of second buffer
2600 2601
 * @consecutive: returns true if there is data in buf_b that is consecutive
 *               to buf_a
A
Adrian Hunter 已提交
2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613
 *
 * If the trace contains TSC we can look at the last TSC of @buf_a and the
 * first TSC of @buf_b in order to determine if the buffers overlap, and then
 * walk forward in @buf_b until a later TSC is found.  A precondition is that
 * @buf_a and @buf_b are positioned at a PSB.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts, or
 * @buf_b + @len_b if there is no non-overlapped data.
 */
static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
						size_t len_a,
						unsigned char *buf_b,
2614
						size_t len_b, bool *consecutive)
A
Adrian Hunter 已提交
2615 2616 2617
{
	uint64_t tsc_a, tsc_b;
	unsigned char *p;
2618
	size_t len, rem_a, rem_b;
A
Adrian Hunter 已提交
2619 2620 2621 2622 2623 2624

	p = intel_pt_last_psb(buf_a, len_a);
	if (!p)
		return buf_b; /* No PSB in buf_a => no overlap */

	len = len_a - (p - buf_a);
2625
	if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
A
Adrian Hunter 已提交
2626 2627 2628 2629 2630 2631
		/* The last PSB+ in buf_a is incomplete, so go back one more */
		len_a -= len;
		p = intel_pt_last_psb(buf_a, len_a);
		if (!p)
			return buf_b; /* No full PSB+ => assume no overlap */
		len = len_a - (p - buf_a);
2632
		if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
A
Adrian Hunter 已提交
2633 2634 2635 2636 2637
			return buf_b; /* No TSC in buf_a => assume no overlap */
	}

	while (1) {
		/* Ignore PSB+ with no TSC */
2638 2639 2640 2641 2642
		if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
			int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);

			/* Same TSC, so buffers are consecutive */
			if (!cmp && rem_b >= rem_a) {
2643 2644
				unsigned char *start;

2645
				*consecutive = true;
2646 2647
				start = buf_b + len_b - (rem_b - rem_a);
				return adj_for_padding(start, buf_a, len_a);
2648 2649 2650 2651
			}
			if (cmp < 0)
				return buf_b; /* tsc_a < tsc_b => no overlap */
		}
A
Adrian Hunter 已提交
2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664

		if (!intel_pt_step_psb(&buf_b, &len_b))
			return buf_b + len_b; /* No PSB in buf_b => no data */
	}
}

/**
 * intel_pt_find_overlap - determine start of non-overlapped trace data.
 * @buf_a: first buffer
 * @len_a: size of first buffer
 * @buf_b: second buffer
 * @len_b: size of second buffer
 * @have_tsc: can use TSC packets to detect overlap
2665 2666
 * @consecutive: returns true if there is data in buf_b that is consecutive
 *               to buf_a
A
Adrian Hunter 已提交
2667 2668 2669 2670 2671 2672 2673 2674 2675 2676
 *
 * When trace samples or snapshots are recorded there is the possibility that
 * the data overlaps.  Note that, for the purposes of decoding, data is only
 * useful if it begins with a PSB packet.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts, or
 * @buf_b + @len_b if there is no non-overlapped data.
 */
unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
				     unsigned char *buf_b, size_t len_b,
2677
				     bool have_tsc, bool *consecutive)
A
Adrian Hunter 已提交
2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688
{
	unsigned char *found;

	/* Buffer 'b' must start at PSB so throw away everything before that */
	if (!intel_pt_next_psb(&buf_b, &len_b))
		return buf_b + len_b; /* No PSB */

	if (!intel_pt_next_psb(&buf_a, &len_a))
		return buf_b; /* No overlap */

	if (have_tsc) {
2689 2690
		found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
						  consecutive);
A
Adrian Hunter 已提交
2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707
		if (found)
			return found;
	}

	/*
	 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
	 * we can ignore the first part of buffer 'a'.
	 */
	while (len_b < len_a) {
		if (!intel_pt_step_psb(&buf_a, &len_a))
			return buf_b; /* No overlap */
	}

	/* Now len_b >= len_a */
	while (1) {
		/* Potential overlap so check the bytes */
		found = memmem(buf_a, len_a, buf_b, len_a);
2708 2709
		if (found) {
			*consecutive = true;
2710
			return adj_for_padding(buf_b + len_a, buf_a, len_a);
2711
		}
A
Adrian Hunter 已提交
2712 2713 2714 2715 2716 2717

		/* Try again at next PSB in buffer 'a' */
		if (!intel_pt_step_psb(&buf_a, &len_a))
			return buf_b; /* No overlap */
	}
}